fix(AMM): prevent orphaned objects, inconsistent ledger state: (#4626)

When an AMM account is deleted, the owner directory entries must be
deleted in order to ensure consistent ledger state.

* When deleting AMM account:
  * Clean up AMM owner dir, linking AMM account and AMM object
  * Delete trust lines to AMM
* Disallow `CheckCreate` to AMM accounts
  * AMM cannot cash a check
* Constrain entries in AuthAccounts array to be accounts
  * AuthAccounts is an array of objects for the AMMBid transaction
* SetTrust (TrustSet): Allow on AMM only for LP tokens
  * If the destination is an AMM account and the trust line doesn't
    exist, then:
    * If the asset is not the AMM LP token, then fail the tx with
      `tecNO_PERMISSION`
    * If the AMM is in empty state, then fail the tx with `tecAMM_EMPTY`
      * This disallows trustlines to AMM in empty state
* Add AMMID to AMM root account
  * Remove lsfAMM flag and use sfAMMID instead
* Remove owner dir entry for ltAMM
* Add `AMMDelete` transaction type to handle amortized deletion
  * Limit number of trust lines to delete on final withdraw + AMMDelete
  * Put AMM in empty state when LPTokens is 0 upon final withdraw
  * Add `tfTwoAssetIfEmpty` deposit option in AMM empty state
  * Fail all AMM transactions in AMM empty state except special deposit
  * Add `tecINCOMPLETE` to indicate that not all AMM trust lines are
    deleted (i.e. partial deletion)
    * This is handled in Transactor similar to deleted offers
  * Fail AMMDelete with `tecINTERNAL` if AMM root account is nullptr
  * Don't validate for invalid asset pair in AMMDelete
* AMMWithdraw deletes AMM trust lines and AMM account/object only if the
  number of trust lines is less than max
  * Current `maxDeletableAMMTrustLines` = 512
  * Check no directory left after AMM trust lines are deleted
  * Enable partial trustline deletion in AMMWithdraw
* Add `tecAMM_NOT_EMPTY` to fail any transaction that expects an AMM in
  empty state
* Clawback considerations
  * Disallow clawback out of AMM account
  * Disallow AMM create if issuer can claw back

This patch applies to the AMM implementation in #4294.

Acknowledgements:
Richard Holland and Nik Bougalis for responsibly disclosing this issue.

Bug Bounties and Responsible Disclosures:
We welcome reviews of the project code and urge researchers to
responsibly disclose any issues they may find.

To report a bug, please send a detailed report to:

    bugs@xrpl.org

Signed-off-by: Manoj Doshi <mdoshi@ripple.com>

src/ripple/protocol/impl/TER.cpp

@@ -45,6 +45,9 @@ transResults()
         MAKE_ERROR(tecAMM_BALANCE,                   "AMM has invalid balance."),
         MAKE_ERROR(tecAMM_INVALID_TOKENS,            "AMM invalid LP tokens."),
         MAKE_ERROR(tecAMM_FAILED,                    "AMM transaction failed."),
+        MAKE_ERROR(tecAMM_EMPTY,                     "AMM is in empty state."),
+        MAKE_ERROR(tecAMM_NOT_EMPTY,                 "AMM is not in empty state."),
+        MAKE_ERROR(tecAMM_ACCOUNT,                   "This operation is not allowed on an AMM Account."),
         MAKE_ERROR(tecCLAIM,                         "Fee claimed. Sequence used. No action."),
         MAKE_ERROR(tecDIR_FULL,                      "Can not add entry to full directory."),
         MAKE_ERROR(tecFAILED_PROCESSING,             "Failed to correctly process transaction."),
@@ -96,6 +99,8 @@ transResults()
         MAKE_ERROR(tecREQUIRES_FLAG,                 "The transaction or part-thereof requires a flag that wasn't set."),
         MAKE_ERROR(tecPRECISION_LOSS,                "The amounts used by the transaction cannot interact."),
         MAKE_ERROR(tecINSUF_RESERVE_SELLER,          "The seller of an object has insufficient reserves, and thus cannot complete the sale."),
+        MAKE_ERROR(tecINCOMPLETE,                    "Some work was completed, but more submissions required to finish."),
+
         MAKE_ERROR(tefALREADY,                     "The exact transaction was already in this ledger."),
         MAKE_ERROR(tefBAD_ADD_AUTH,                "Not authorized to add account."),
         MAKE_ERROR(tefBAD_AUTH,                    "Transaction's public key is not authorized."),